#ex3
profit=int(input())
if profit <= 10:
    reward = profit * 0.1
    print(reward)
elif profit <= 20:
    reward = 10 * 0.1 + (profit - 10) * 0.075
    print(reward)
elif profit <= 40:
    reward = 10 * 0.1 + 10 * 0.075 + (profit - 20) * 0.05
    print(reward)
elif profit <= 60:
    reward = 10 * 0.1 + 10 * 0.075 + 20 * 0.05 + (profit - 40) * 0.03
    print(reward)
elif profit <= 100:
    reward = 10 * 0.1 + 10 * 0.075 + 20 * 0.05 + 20 * 0.03 + (profit - 60) * 0.015
    print(reward)
else:
    reward = 10 * 0.1 + 10 * 0.075 + 20 * 0.05 + 20 * 0.03 + 40 * 0.015 + (profit - 100) * 0.01
    print(reward)




